/**
 * Copyright (c) 2005-2012 https://github.com/zhangkaitao
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.github.zhangkaitao.shiro.chapter22.jcaptcha;

import org.apache.shiro.web.filter.AccessControlFilter;
import org.apache.shiro.web.util.WebUtils;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

/**
 * 验证码过滤器
 * <p>
 * User: Zhang Kaitao
 * <p>
 * Date: 13-3-22 下午4:01
 * <p>
 * Version: 1.0
 */
public class JCaptchaValidateFilter extends AccessControlFilter {

	private boolean jcaptchaEbabled = true;// 是否开启验证码支持

	private String jcaptchaParam = "jcaptchaCode";// 前台提交的验证码参数名

	private String failureKeyAttribute = "shiroLoginFailure"; // 验证码验证失败后存储到的属性名

	public void setJcaptchaEbabled(boolean jcaptchaEbabled) {
		this.jcaptchaEbabled = jcaptchaEbabled;
	}

	public void setJcaptchaParam(String jcaptchaParam) {
		this.jcaptchaParam = jcaptchaParam;
	}

	public void setFailureKeyAttribute(String failureKeyAttribute) {
		this.failureKeyAttribute = failureKeyAttribute;
	}

	@Override
	protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue)
			throws Exception {
		// 1、设置验证码是否开启属性，页面可以根据该属性来决定是否显示验证码
		request.setAttribute("jcaptchaEbabled", jcaptchaEbabled);

		HttpServletRequest httpServletRequest = WebUtils.toHttp(request);
		// 2、判断验证码是否禁用 或不是表单提交（允许访问）
		if (jcaptchaEbabled == false || !"post".equalsIgnoreCase(httpServletRequest.getMethod())) {
			return true;
		}
		// 3、此时是表单提交，验证验证码是否正确
		String kaptchaReceived = httpServletRequest.getParameter(jcaptchaParam);

		String kaptchaExpected = (String) httpServletRequest.getSession()
				.getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);

		return kaptchaReceived.equalsIgnoreCase(kaptchaExpected);
	}

	@Override
	protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
		// 如果验证码失败了，存储失败key属性
		request.setAttribute(failureKeyAttribute, "jCaptcha.error");
		return true;
	}
}
